Cleansense Charcoal Filters Are Made From The Highest Quality Materials To Provide The Longest Life Possible And Keep Your Range Hood Operating At Peak Performance. (Ul)(Li)Bppf30 Filters Are Sold In A Pack Of Two; Two Are Required For Replacement(/Li)(Li)Cleansense Filters Have A Stripe Feature On One Side Which Changes Color To Indicate When It Is Time To Replace The Filter(/Li)(Li)Designed For Non-Duct Installation Of The 30" Wide Qp Series Range Hoods(/Li)(/Ul)